Preventing Data Transfer Time-Out From Hosts; Interface Selection; Printer Language And Control Codes - Epson Stylus Color 1520 Service Manual

EPSON Stylus COLOR 1520
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Sending BDC-ST through DBIN register
When State-Reply is set "ON", by ST from Type-B I/F, sending BDC-ST through DBIN register is started.
When State-Reply is started, "Start" and "End" of BDC-ST characters are announced by sending the Main
command 0Eh.

1.3.4 Preventing Data Transfer Time-out from Hosts

Generally, hosts abandon data transfer to peripherals when a peripheral is BUSY continuously for dozens of
seconds. To prevent this kind of time-out, the printer receives data very slowly, several bytes per minute,
even if the printer is in a busy state. This slowdown starts when the remainder of the input buffer drops under
several hundred bytes. Finally, the printer is BUSY continuously when the input buffer is full.

1.3.5 Interface Selection

The EPSON Stylus COLOR 1520 has three types of interfaces available: parallel, serial, and optional
interfaces. Each interface can be selected manually or automatically. Both modes are selected thorough the
default setting mode.
Manual selection
One of 3 interfaces selected through the default setting mode. The selected interface is fixed.
Automatic selection
When the printer is in this mode, the printer is initialized to the idle state when it is turned on. Then the
interface that receives data first is selected. When the host stops data transfer and the printer is in the
stand-by state for the specific time, the printer returns to the idle state. As long as the host sends data or
the printer interface is in busy state, the selected interface remains active.
Interface State and Interface Selection
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When the parallel interface is not selected, the interface goes into the busy state.
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When the serial interface is not selected, the interface sets the DTR signal MARK.
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When the printer is initialized or returned to the idle state, the parallel interface goes into the ready
state and the serial interface sets the DTR signal SPACE.
Note) An interrupt signal such as the /INIT signal on the parallel interface is ignored while that
interface is not selected.

1.3.6 Printer language and Control Codes

Printer languages and control codes
1-22
ESC/PC
IBM X24E
EPSON Remote